The Present Disclosure relates generally to optical fiber ferrule assemblies, and, more particularly, to a multi-fiber ferrule assembly with an adjacent lens structure.
Systems for interconnecting optical fibers typically utilize mating ferrule assemblies to facilitate handling and accurate positioning of the fibers. The optical fibers are secured within a ferrule body, with an end surface of each fiber being positioned generally flush with or slightly protruding from an end face of the ferrule body. The end surfaces or faces of the fibers are then polished to a desired finish. When complementary ferrules assemblies are mated, each optical fiber of a ferrule assembly is coaxially positioned with a mating optical fiber of the other ferrule assembly.
In some applications, the end faces of the mating optical fibers physically contact one another in order to effect signal transmission between the mating optical fiber pair. In such applications, various factors may reduce the efficiency of the light transmission between the optical fiber pair such as irregularities, burrs or scratches in the fiber end faces, misalignment of the fibers as well as dust or debris between the fibers at the mating interface.
Due to the small optical path relative to the size of any foreign objects such as dust or debris, any such foreign objects will likely interfere with the transmission of light. Expanded beam connectors expand the width of the optical beam and transmit the beam over an air gap between the connectors. By expanding the beam, the relative size difference between the dust or debris and the beam is increased which thus reduces the impact of any dust or debris as well as any misalignment on the efficiency of the light transmission. As a result, expanded beam optical fiber connectors are often used in dirty and high vibration environments.
Expanded beam connectors include a lens mounted adjacent an end face of each fiber. Two types of lenses are commonly used—collimating and cross-focusing. A collimating lens receives the light from the fiber and expands the beam to a relatively large diameter. When using a collimating lens, a second lens and ferrule assembly is similarly configured with the lens positioned adjacent the end face of the second fiber for receiving the expanded beam, and refocuses the beam at the end face of the second fiber. A cross-focusing lens receives the light from the fiber, expands it to a relatively large diameter, and then focuses the light from the relatively large diameter at a specific focal point. With cross-focusing lenses, the lens and ferrule assembly may be mated with either another lens and ferrule assembly having a cross-focusing lens or with a non-lensed ferrule assembly, as is known in the art. While lenses for alignment with a ferrule assembly having a single optical fiber are typically spherical, lenses for alignment with multi-fiber ferrule assemblies are more complex in nature, and tolerances typically must be controlled more tightly. Accordingly, it is desirable to provide a multi-fiber lensed ferrule assembly that is less complex, easy to assemble and has improved performance.